lms: Reduce Rx gain from 47 to 34 dB

Initially, Rx gain was hardcoded to be 47. This was too high for our
setup and we were constantly getting "clipping detected" messages.

Reducing Rx gain to 34 solved the issue. However, it looks like gains
should be controlled through configuration files.

Change-Id: I30580f18c4ad630c09f725b1d24c125fc3119809

Transceiver52M/device/lms/LMSDevice.cpp

@@ -319,7 +319,7 @@ double LMSDevice::setRxGain(double dB, size_t chan)
 		return 0.0;
 	}
 
-	dB = 47.0;
+	dB = 34.0;
 
 	if (dB > maxRxGain())
 		dB = maxRxGain();